Widely available lignite ash-slag, which is a waste product presently of no use, poses an environmental problem. The present invention uses this environmental waste mineral product as a main component in making a construction board, such as a wall panel, isolated panel, floor board, etc.
It is conventional to use a construction board made of composite material, such as cement or gypsum mixed with wood particles. However, boards made of these composite materials are not economical and/or have weak or undesirable physical property in comparison with a board of the present invention. As disclosed in Obzornaia News Magazine, Number 2 (1987), manufacturing one cube meter (1 m.sup.3) of a cement board consumes the following:
cement 770 kg PA0 wood 280 kg PA0 chemical product 50 kg PA0 electrical energy 140-290 kwh PA0 thermal energy 400 kcal PA0 manufacture (human work) consumption 27 hours.
As evidenced above a cement board made from a mixture of cement and wood particles requires a huge consumption of energy and labor in the making thereof.